The Lost Voices of the Gods (Interview with Julian Jaynes)

The hypothesis: Ancient man was virtually an automaton, who had no concept of self-fulfillment, no sense of sin or the brevity of life,
no existential doubt or anxiety. He acted on orders from voices that he actually heard within his head - the voices of gods, who told him what to do and how to solve his problems. His mind was thus divided into an executive part called god, probably based in the right hemisphere of the brain, and a follower part called man.